Strong yet ductile nanolamellar high-entropy alloys by additive manufacturing.

Additive manufacturing produces net-shaped components layer by layer for engineering applications1-7. The additive manufacture of metal alloys by laser powder bed fusion (L-PBF) involves large temperature gradients and rapid cooling2,6, which enables microstructural refinement at the nanoscale to achieve high strength. However, high-strength nanostructured alloys produced by laser additive manufacturing often have limited ductility3. Here we use L-PBF to print dual-phase nanolamellar high-entropy alloys (HEAs) of AlCoCrFeNi2.1 that exhibit a combination of a high yield strength of about 1.3 gigapascals and a large uniform elongation of about 14 per cent, which surpasses those of other state-of-the-art additively manufactured metal alloys. The high yield strength stems from the strong strengthening effects of the dual-phase structures that consist of alternating face-centred cubic and body-centred cubic nanolamellae; the body-centred cubic nanolamellae exhibit higher strengths and higher hardening rates than the face-centred cubic nanolamellae. The large tensile ductility arises owing to the high work-hardening capability of the as-printed hierarchical microstructures in the form of dual-phase nanolamellae embedded in microscale eutectic colonies, which have nearly random orientations to promote isotropic mechanical properties. The mechanistic insights into the deformation behaviour of additively manufactured HEAs have broad implications for the development of hierarchical, dual- and multi-phase, nanostructured alloys with exceptional mechanical properties.

The contributions of individual countries and regions to the global radiative forcing.

Knowing the historical relative contribution of greenhouse gases (GHGs) and short-lived climate forcers (SLCFs) to global radiative forcing (RF) at the regional level can help understand how future GHGs emission reductions and associated or independent reductions in SLCFs will affect the ultimate purpose of the Paris Agreement. In this study, we use a compact Earth system model to quantify the global RF and attribute global RF to individual countries and regions. As our evaluation, the United States, the first 15 European Union members, and China are the top three contributors, accounting for 21.9 ± 3.1%, 13.7 ± 1.6%, and 8.6 ± 7.0% of global RF in 2014, respectively. We also find a contrast between developed countries where GHGs dominate the RF and developing countries where SLCFs including aerosols and ozone are more dominant. In developing countries, negative RF caused by aerosols largely masks the positive RF from GHGs. As developing countries take measures to improve the air quality, their negative contributions from aerosols will likely be reduced in the future, which will in turn enhance global warming. This underlines the importance of reducing GHG emissions in parallel to avoid any detrimental consequences from air quality policies.

Endoplasmic reticulum stress is upregulated in inflammatory bowel disease and contributed TLR2 pathway-mediated inflammatory response.

OBJECTIVE: Endoplasmic reticulum stress (ERS) and Toll-like receptor 2 (TLR2) signaling play an important role in inflammatory bowel disease (IBD); however, the link between TLR2 and ERS in IBD is unclear. This study investigated whether Thapsigargin (TG) -induced ER protein expression levels contributed to TLR2-mediated inflammatory response. METHODS: The THP-1 cells were treated with TLR2 agonist (Pam3CSK4), ERS inducer Thapsigargin (TG) or inhibitor (TUDCA). The mRNA expressions of TLR1-TLR10 were detected by qPCR. The production and secretion of inflammatory factors were detected by PCR and ELISA. Immunohistochemistry was used to detect the expressions of GRP78 and TLR2 in the intestinal mucosa of patients with Crohn's disease (CD). The IBD mouse model was established by TNBS in the modeling group. ERS inhibitor (TUDCA) was used in the treatment group. RESULTS: The expression of TLRs was detected via polymerase chain reaction (PCR) in THP-1 cells treated by ERS agonist Thapsigargin (TG). According to the findings, TG could promote TLR2 and TLR5 expression. Subsequently, in TLR2 agonist Pam3CSK4 induced THP-1 cells, TG could lead to increased expression of the inflammatory factors such as TNF-α, IL-1ß and IL-8, and ERS inhibitor (TUDCA) could block this effect. However, Pam3CSK4 did not significantly impact the GRP78 and CHOP expression. Based upon the immunohistochemical results, TLR2 and GRP78 expression were significantly increased in the intestinal mucosa of patients with Crohn's disease (CD). For in vivo experiments, TUDCA displayed the ability to inhibit intestinal mucosal inflammation and reduce GRP78 and TLR2 proteins. CONCLUSIONS: ERS and TLR2 is upregulated in inflammatory bowel disease, ERS may promote TLR2 pathway-mediated inflammatory response. Moreover, ERS and TLR2 signaling could be novel therapeutic targets for IBD.

[Research progress on structures, activities, and biosynthesis of blazeispirol compounds from Agaricus blazei].

Agaricus blazei is a rare medicinal and edible fungus with a crispy taste and delicious flavor. Both fruiting body and mycelium are rich in polysaccharides, sterols, terpenoids, peptides, lipids, polyphenols, and other active ingredients, which have strong pharmacological activities such as anti-tumor, lipid-lowering, glucose-lowering, immunomodulation, optimization of intestinal flora, and anti-oxidation. Therefore, it is a kind of fungal resource with a great prospect of edible and medicinal development. Among the reported chemical components of A. blazei, blazeispirol is a series of sterol compounds unique to A. blazei, which has a spiral structure and is different from classical steroids. It is an important active ingredient found in the mycelium of A. blazei and has significant hepatoprotective activity. It can be used as a phylogenetic and chemotaxonomic marker of A. blazei strains and is considered an excellent lead compound for drug development. According to the skeleton structure characteristics, the 17 discovered blazeispirol compounds can be divided into two types: blazeispirane and problazeispirane. In order to further explore the resource of blazeispirol compounds of A. blazei, the discovery, isolation, structure, biological activity, and biosynthetic pathways of blazeispirol compounds of A. blazei were systematically reviewed. Besides, the metabolic regulation strategies related to the fermentation synthesis of blazeispirol A by A. blazei were discussed. This review could provide a reference for the efficient synthesis and development of blazeispirol compounds, the research and development of related drugs and functional foods, and the quality improvement of A. blazei and other medicinal and edible fungi resources and derivatives.

Humoral and cellular immunity of two-dose inactivated COVID-19 vaccination in Chinese children: A prospective cohort study.

Children are the high-risk group for COVID-19, and in need of vaccination. However, humoral and cellular immune responses of COVID-19 vaccine remain unclear in vaccinated children. To establish the rational immunization strategy of inactivated COVID-19 vaccine for children, the immunogenicity of either one dose or two doses of the vaccine in children was evaluated. A prospective cohort study of 322 children receiving inactivated COVID-19 vaccine was established in China. The baseline was conducted after 28 days of the first dose, and the follow-up was conducted after 28 days of the second dose. The median titers of receptor binding domain (RBD)-IgG, and neutralizing antibody (NAb) against prototype strain and Omicron variant after the second dose increased significantly compared to those after the first dose (first dose: 70.0, [interquartile range, 30.0-151.0] vs. second dose: 1261.0 [636.0-2060.0] for RBD-IgG; 2.5 [2.5-18.6] vs. 252.0 [138.6-462.1] for NAb against prototype strain; 2.5 [2.5-2.5] vs. 15.0 [7.8-26.5] for NAb against Omicron variant, all p < 0.05). The flow cytometry results showed that the first dose elicited SARS-CoV-2 specific cellular immunity, while the second dose strengthened SARS-CoV-2 specific IL-2+ or TNF-α+  monofunctional, IFN-γ+ TNF-α+  bifunctional, and IFN-γ- IL-2+ TNF-α+ multifunctional CD4+ T cell responses (p < 0.05). Moreover, SARS-CoV-2 specific memory T cells were generated after the first vaccination, including the central memory T cells and effector memory T cells. The present findings provide scientific evidence for the vaccination strategy of the inactive vaccines among children against COVID-19 pandemic.

LMWP (S3-3) from the Larvae of Musca domestica Alleviate D-IBS by Adjusting the Gut Microbiota.

Diarrhea-based Irritable Bowel Syndrome (D-IBS) and diarrhea are both associated with ecological imbalance of the gut microbiota. Low Molecular Weight Peptides (LMWP) from the larvae of Musca domestica have been shown to be effective in the treatment of diarrhea and regulation of gut microbiota. Meanwhile, the single polypeptide S3-3 was successfully isolated and identified from LMWP in our previous studies. It remains unclear exactly whether and how LMWP (S3-3) alleviate D-IBS through regulating gut microbiota. We evaluated the gut microbiota and pharmacology to determine the regulation of gut microbiota structure and the alleviating effect on D-IBS through LMWP (S3-3). The rates of loose stools, abdominal withdrawal reflex (AWR) and intestinal tract motility results revealed that LMWP (S3-3) from the larvae of Musca domestica had a regulating effect against diarrhea, visceral hypersensitivity and gastrointestinal (GI) dysfunction in D-IBS model mice. Additionally, 16S rRNA gene sequencing was utilized to examine the gut microbiota, which suggests that LMWP induce structural changes in the gut microbiota and alter the levels of the following gut microbiota: Bacteroidetes, Proteobacteria and Verrucomicrobia. LMWP putatively functioned through regulating 5-HT, SERT, 5-HT2AR, 5-HT3AR and 5-HT4R according to the results of ELISA, qRT-PCR and IHC. The findings of this study will contribute to further understanding how LMWP (S3-3) attenuate the effects of D-IBS on diarrhea, visceral hypersensitivity and GI dysfunction.

Maximum Correntropy with Variable Center Unscented Kalman Filter for Robust Power System State Estimation.

The robust Kalman filter with correntropy loss has received much attention in recent years for forecasting-aided state estimation in power systems, since it efficiently reduces the negative influence of various abnormal situations, such as non-Gaussian communication, changing environment, and instrument failures, and obviously improves the stability of power systems. However, the existing correntropy-based robust Kalman filters usually use the Gaussian function with a fixed center as the kernel function in correntropy, which may not be a suitable choice in practical applications of power system forecasting-aided state estimation (PSSE). To address this issue, a new and robust unscented Kalman filter, called the maximum correntropy with variable center unscented Kalman filter (MCVUKF), is proposed in this paper for PSSE. Specifically, MCVUKF adopts an extended version of correntropy, whose center can be located at any position, to replace the original correntropy in an unscented Kalman filter to improve the performance in PSSE. Moreover, by using an exponential function of the innovation vector to adjust a covariance matrix, an enhanced MCVUKF (En-MCVUKF) method is also developed for suppressing the influence of bad data to the innovation vector and further improving the accuracy of PSSE. Finally, extensive simulations have been conducted on IEEE 14-bus, 30-bus, and 57-bus test power systems, and the simulation results have shown the superiority of the proposed MCVUKF and En-MCVUKF methods compared with several related state-of-the-art Kalman filter methods.

Insights into heat response mechanisms in Clematis species: physiological analysis, expression profiles and function verification.

KEY MESSAGE: Our results provide insights into heat response mechanisms among Clematis species. Overexpressing CvHSFA2 enhanced the heat resistance of yeast and silencing NbHSFA2 reduced the heat resistance of tobacco. Clematis species are commonly grown in western and Japanese gardens. Heat stress can inhibit many physiological processes mediating plant growth and development. The mechanism regulating responses to heat has been well characterized in Arabidopsis thaliana and some crops, but not in horticultural plants, including Clematis species. In this study, we found that Clematis alpina 'Stolwijk Gold' was heat-sensitive whereas Clematis vitalba and Clematis viticella 'Polish Spirit' were heat-tolerant based on the physiological analyses in heat stress. Transcriptomic profiling identified a set of heat tolerance-related genes (HTGs). Consistent with the observed phenotype in heat stress, 41.43% of the differentially expressed HTGs between heat treatment and control were down-regulated in heat-sensitive cultivar Stolwijk Gold, but only 9.80% and 20.79% of the differentially expressed HTGs in heat resistant C. vitalba and Polish Spirit, respectively. Co-expression network, protein-protein interaction network and phylogenetic analysis revealed that the genes encoding heat shock transcription factors (HSFs) and heat shock proteins (HSPs) may played an essential role in Clematis resistance to heat stress. Two clades of heat-induced CvHSFs were further identified by phylogenetic tree, motif analysis and qRT-PCR. Ultimately, we proposed that overexpressing CvHSFA2-2 could endow yeast with high temperature resistance and silencing its homologous gene NbHSFA2 reduced the heat resistance of tobacco. This study provides first insights into the diversity of the heat response mechanisms among Clematis species.

One Heat Shock Transcription Factor Confers High Thermal Tolerance in Clematis Plants.

Clematis plants play an important role in botanical gardens. Heat stress can destroy the activity, state and conformation of plant proteins, and its regulatory pathway has been well characterized in Arabidopsis and some crop plants. However, the heat resistance response mechanism in horticultural plants including Clematis has rarely been reported. Here, we identified a heat-tolerant clematis species, Clematis vitalba. The relative water loss and electrolytic leakage were significantly lower under heat treatment in Clematis vitalba compared to Stolwijk Gold. Differential expression heat-tolerant genes (HTGs) were identified based on nonparametric transcriptome analysis. For validation, one heat shock transcription factor, CvHSF30-2, extremely induced by heat stimuli in Clematis vitalba, was identified to confer tolerance to heat stress in Escherichia coli and Saccharomyces cerevisiae. Furthermore, silencing of HSF30-2 by virus-induced gene silencing (VIGS) led to heat sensitivity in tobacco and Clematis, suggesting that the candidate heat-resistant genes identified in this RNA-seq analysis are credible and offer significant utility. We also found that CvHSF30-2 improved heat tolerance of Clematis vitalba by elevating heat shock protein (HSP) expression, which was negatively regulated by CvHSFB2a. Taken together, this study provides insights into the mechanism of Clematis heat tolerance and the findings can be potentially applied in horticultural plants to improve economic efficiency through genetic approaches.

Augment of Oxidative Damage with Enhanced Photodynamic Process and MTH1 Inhibition for Tumor Therapy.

Tumor cells adapt to reactive oxygen species (ROS) attacking by launching DNA damage repairing mechanisms such as nucleotide pool sanitizing enzyme mutt homologue 1 (MTH1) to mitigate the oxidatively induced DNA lesions, which could greatly limit the therapeutic efficiency of current oxidation therapy. Here, an amplified oxidative damage strategy for tumor therapy was proposed that was focused not only on the enhancement of ROS generation but also the inhibition of subsequent MTH1 enzyme activity simultaneously. In our formulation, mesoporous silica-coated Prussian blue nanoplatforms (PB@MSN) with excellent catalase-like activity and drug loading capability were employed to encapsulate MTH1 inhibitor TH287, followed by the modification of tetraphenylporphrin zinc (Zn-Por) via metallo-supramolecular coordination (PMPT), where Zn-Por behaved as photodynamic and fluorescence imaging agents, as well as acid-responsive gatekeepers. The intelligent PMPT nanosystems could induce the decomposition of H2O2 to relieve the hypoxic tumor environment, thus elevating the generation of singlet oxygen for improved oxidative damage. In the meantime, controllable-released TH287 from pores could hinder MTH1-mediated damage repairing process and aggravate oxidative damage, thereby resulting in cellular toxicity as well as tumor growth inhibition.

Biochemical and genetic characteristics of 40 neonates with carnitine deficiency. / 40ä¾‹è‚‰ç¢±ç¼ºä¹ç—‡æ–°ç”Ÿå„¿çš„ç”ŸåŒ–å’Œé—ä¼ å­¦ç‰¹å¾.

OBJECTIVES: Primary carnitine deficiency (PCD) is a rare fatty acid metabolism disorder that can cause neonatal death. This study aims to analyze carnitine levels and detect SLC22A5 gene in newborns with carnitine deficiency, to provide a basis for early diagnosis of PCD, and to explore the relationship between carnitine in blood and SLC22A5 genotype. METHODS: A total of 40 neonates with low free carnitine (C0<10 µmol/L) in blood were the subjects of the study. SLC22A5 gene was detected by Sanger sequencing to analyze the value of carnitine, the results of gene test and their relationship. RESULTS: A total of 15 variants of SLC22A5 gene were detected, including 11 pathogenic or likely pathogenic variants and 4 variants of uncertain significance. There were 5 new mutations: c.288delG (p.G96fsX33), c.744_745insTCG (p.M258_L259insS), c.752A>G (p.Y251C), c.495 C>A (p.R165E), and c.1298T>C (p.M433T). We found 14 PCD patients including 2 homozygous mutations and 12 heterozygous mutations, 14 with 1 mutation, and 12 with no mutation among 40 children. The C0 concentration of children with SLC22A5 gene homozygous or complex heterozygous mutations was (4.95±1.62) µmol/L in the initial screening, and (3.90±1.33) µmol/L in the second screening. The C0 concentration of children with no mutation was (7.04±2.05) µmol/L in the initial screening, and (8.02±2.87) µmol/L in the second screening. There were significant differences between children with homozygous or compound heterozygous mutations and with no mutation in C0 concentration of the initial and the second screening (both P<0.05), as well as between children with truncated mutation and with untruncated mutation in C0 concentration of the initial screening (P=0.022). CONCLUSIONS: There are 5 new mutations which enriched the mutation spectrum of SLC22A5 gene. C0<5 µmol/L is highly correlated with SLC22A5 gene homozygous or compound heterozygous mutations. Children with truncated mutation may have lower C0 concentration than that with untruncated mutation in the initial screening.

Newborn meconium and urinary metabolome response to maternal gestational diabetes mellitus: a preliminary case-control study.

Recently, the number of women suffering from gestational diabetes mellitus (GDM) has risen dramatically. GDM attracts increasing attention due to its potential harm to the heath of both the fetus and the mother. We designed this case-control study to investigate the metabolome response of newborn meconium and urine to maternal GDM. GDM mothers (n = 142) and healthy controls (n = 197) were recruited during June-July 2012 in Xiamen, China. The newborns' metabolic profiles were acquired using liquid chromatography coupled to mass spectrometry. The data showed that meconium and urine metabolome patterns clearly discriminated GDM cases from controls. Fourteen meconium metabolic biomarkers and three urinary metabolic biomarkers were tentatively identified for GDM. Altered levels of various endogenous biomarkers revealed that GDM may induce disruptions in lipid metabolism, amino acid metabolism, and purine metabolism. An unbalanced lipid pattern is suspected to be a GDM-specific feature. Furthermore, the relationships between the potential biomarkers and GDM risk were evaluated by binary logistic regression and receiver operating characteristic analysis. A combined model of nine meconium biomarkers showed a great potential in diagnosing GDM-induced disorders.

A nested case-control study indicating heavy metal residues in meconium associate with maternal gestational diabetes mellitus risk.

BACKGROUND: Environmental pollutant exposure may play certain roles in the pathogenesis and progression of diabetes mellitus including gestational diabetes mellitus (GDM). We hypothesize that heavy metal exposure may trigger GDM during pregnancy. The objective of this study was to investigate the possible associations between selected heavy metal exposure and GDM risk. METHODS: This investigation is a retrospective case-control study nested within a cohort of 1359 pregnant women. These participants were recruited in Xiamen Maternity and Child Care Hospital, China, during June to July, 2012. All their newborns' meconium samples were collected. By reviewing the antenatal care records, 166 GDM mothers were screened out from the 1359 participants; 137 of 166 GDM mothers offered their newborns' meconium samples for the metal analysis. Those 137 mothers were set as the case group. Similarly, 294 healthy mothers without any gestational complication were initially screened out from the rest 1193 non-GDM mothers. 190 of the 294 healthy mothers offered their newborns' meconium samples for the metal analysis. Those 190 mothers were set as the control group. Arsenic (As), mercury (Hg), lead (Pb), cadmium (Cd), and chromium (Cr) levels in these case-control meconium samples were measured by inductively coupled plasma mass spectrometry. The possible association between the metal levels and maternal GDM risk of studied subjects was assessed by binary logistic regression. RESULTS: GDM prevalence of 12.21% was observed in the investigated 1359 participants. The concentrations of As, Hg, Cr and Cd in studied cases were significantly higher (p < 0.05) than those of controls. After adjustments for maternal age, pre-pregnant body mass index, gravidity, parity, hepatitis B virus infection, and newborn sex, As, Cd and Cr were found to be positively associated with GDM prevalence in dose-dependent manners. Among them, As was detected in all samples and its levels associated the maternal GDM with the adjusted odds ratios of 3.28 [95% CI 1.24, 8.71], 3.35 [95% CI 1.28, 8.75] and 5.25 [95% CI 1.99, 13.86] for the 2(nd), 3(rd) and 4(th) quartiles, respectively. CONCLUSIONS: The present work implies that exposure to some of the selected metals (noticeably As) may contribute to maternal GDM risk during pregnancy.

Arsenic levels from different land-use settings in Pakistan: Bio-accumulation and estimation of potential human health risk via dust exposure.

The present study aims at assessing arsenic (As) levels in outdoor dust and human exposure risks at different land use setting (i.e., rural, industrial, urban) from Punjab, Pakistan. The results showed higher As concentrations (mg/kg) in all the sample types ( i.e., dust, hair and nail) collected from industrial sites (9.78, 2.36, 2.5) followed by urban (7.59, 0.38, 0.88) and rural sites (6.95, 0.52, 1.12), respectively. In the current study, we also carried out human risk assessment via contaminated dust exposure, which suggested that dust ingestion is the major route of As contamination for the associated population, followed by the inhalation and dermal contact, at all studied land use settings. Hazard Index (HI) calculated for non-carcinogenic health risks for adults showed higher values at industrial (0.65) and urban (0.53) sites, which reflected that dust exposure is the major contributing source of human arsenic burden and may pose several adverse health effects. Carcinogenic risk values showed that at industrial areas the risk of carcinogenesis to the associated population is mainly due to As contaminated dust exposure. Hair (60%) and nail samples (70%) collected from industrial land use were found above the WHO threshold limit of 1mg/kg, suggested high risks for human health in the studied area. The results of the present study would be useful for assessing the human health risks due to arsenic contamination via dust exposure in different parts of country.

Toxic metals signature in the human seminal plasma of Pakistani population and their potential role in male infertility.

Aims of this study were to provide firsthand data on the incidence of trace metals in human seminal plasma and find possible correlations between levels of toxic metals and semen quality of Pakistani population. Human semen samples were collected from male partners of couples undergoing infertility assessment at the National Institute of Health Islamabad (Pakistan). We investigated seventy-five seminal plasma samples, which were further categorized into three groups (normozoospermia, oligozoospermia and azoospermia) according to WHO guidelines. The concentration of 17 different toxic metals in human seminal plasma was determined simultaneously by using Inductively coupled plasma mass spectrometry (ICP-MS). Out of 17 trace metals, Cd and Ni showed significant difference (p < 0.05) among three monitored groups. Ni and Cd concentrations in the seminal plasma were negatively correlated with sperm concentration (r = -0.26, -0.29) and motility (r = -0.33, -0.37), respectively. This study suggested that exposure of Ni and Cd is mainly related with the consumption of contaminated dietary items, including ghee (cooking oil), flour and other agri-products. In some semen samples, the concentrations of Sn, V, Cu, Pb, Cr and Hg exhibited high levels suggesting a recent human exposure to surrounding sources. In Pakistani human semen samples, the levels of trace metals were lower and/or comparable to that found in populations of other countries. The results show the first evidence of the effect of toxic metals on semen quality and male infertility in Pakistan.

[Establishment of hemophilia A patient-specific inducible pluripotent stem cells with urine cells].

OBJECTIVE To generate hemophilia A (HA) patient-specific inducible pluripotent stem cells (iPSCs) and induce endothelial differentiation. METHODS Tubular epithelial cells were isolated and cultured from the urine of HA patients. The iPSCs were generated by forced expression of Yamanaka factors (Oct4, Sox2, c-Myc and Klf4) using retroviruses and characterized by cell morphology, pluripotent marker staining and in vivo differentiation through teratoma formation. Induced endothelial differentiation of the iPSCs was achieved with the OP9 cell co-culture method. RESULTS Patient-specific iPSCs were generated from urine cells of the HA patients, which could be identified by cell morphology, pluripotent stem cell surface marker staining and in vivo differentiation of three germ layers. The teratoma experiment has confirmed that such cells could differentiate into endothelial cells expressing the endothelial-specific markers CD144, CD31 and vWF. CONCLUSION HA patient-specific iPSCs could be generated from urine cells and can differentiate into endothelial cells. This has provided a new HA disease modeling approach and may serve as an applicable autologous cell source for gene correction and cell therapy studies for HA.

Pooling samples for "top-down" molecular exposomics research: the methodology.

BACKGROUND: Exposomics is the cutting-edge concept of screening the environmental risk factors for disease. In the novel "top-down" approach, we estimate the molecular exposome by measuring all body fluid analytes in a case-controlled study. However, to detect diverse pollutants, a sufficient sample size and multiple analytical methods are required. This may lead to dramatically increased costs and research workload. METHODS: To help reduce complexity, we suggest a sample pooling strategy along with a scheme for combining both general unknown or multi-targeted screening with targeted analysis. The sample pooling method was tested using computer simulations. RESULTS: By comprehensively analysis of pooled samples, it is possible to identify environmental risk factors. Factors are initially screened in the pooled case and control population samples, then in the randomized grouped and pooled case and control subpopulation samples. In the sample grouping, five or more pools were suggested for groups having 30 individuals per pool. CONCLUSIONS: This study suggests that sample pooling is a useful strategy for exposomics research, which provides a hypothesis-free method for pollutant risk screening.

Effects of water soluble PM2.5 extracts exposure on human lung epithelial cells (A549): A proteomic study.

Exposure to airborne particulate matter (PM)2.5, a PM with aerodynamic diameter of less than 2.5 µm, is known to be associated with a variety of adverse health effects. However, the molecular mechanisms involved in fine PM toxicity are still not well characterized. The present study aims to provide new insights into the cytotoxicity of PM2.5 on human lung epithelial cells (A549) at the proteomic level. Two-dimensional difference gel electrophoresis revealed a total of 27 protein spots, whose abundance were significantly altered in A549 cells exposed to water-soluble PM2.5 extracts (WSPE). Among these, 12 spots were upregulated while 15 were downregulated. Twenty-two proteins were further identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass/mass spectrometry and database search. The results revealed that oxidative stress, metabolic disturbance, dysregulation of signal transduction, aberrant protein synthesis and degradation, as well as cytoskeleton disorganization are major factors contributing to WSPE-mediated toxicity in human lung cells. It is further proposed that induction of apoptosis through p53, c-Myc and p21 pathways may be one of the key toxicological events occurred in A549 cells under WSPE stress. The data obtained here will aid our understanding of the toxic mechanisms related to PM2.5, and develop useful biomarkers indicative of inhalable PM2.5 exposure.

Proteomic analysis of perfluorooctane sulfonate-induced apoptosis in human hepatic cells using the iTRAQ technique.

Perfluorooctane sulfonate (PFOS) is one of the most commonly used perfluorinated compounds, whose environmental exposure has been associated with a number of adverse health outcomes. However, the molecular mechanisms involved in PFOS toxicity are still not well elucidated. In the present study, we applied iTRAQ labeling quantitative proteomic technology to investigate the differential protein expression profiles of non-tumor human hepatic cells (L-02) exposed to PFOS. A total of 18 proteins were differentially expressed in a dose-dependent manner in PFOS-treated cells versus the control. Among these, 11 proteins were up-regulated and 7 were down-regulated. Gene ontology analysis indicated that PFOS would exert toxic effects on L-02 cells by affecting multiple biological processes, including protein biosynthesis and degradation, mRNA processing and splicing, transcription, signal transduction and transport. Furthermore, the proteomic results especially proposed that the inhibition of HNRNPC, HUWE1 and UBQLN1, as well as the induction of PAF1 is involved in the activation of the p53 and c-myc signaling pathways, which then trigger the apoptotic process in L-02 cells exposed to PFOS. Overall, these data will aid our understanding of the mechanisms responsible for PFOS-mediated hepatotoxicity, and develop useful biomarkers for monitoring and evaluating PFOS contamination in the environment.

The Dominant Role of Recrystallization and Grain Growth Behaviors in the Simulated Welding Heat-Affected Zone of High-Mn Steel.

Single-pass-welding thermal cycles with different peak temperatures (Tp) were reproduced by a Gleeble 3800 to simulate the heat-affected zone (HAZ) of a Fe-24Mn-4Cr-0.4C-0.3Cu (wt.%) high manganese austenitic steel. Then, the effect of Tp on the microstructure and mechanical properties of the HAZ were investigated. The results indicate that recrystallization and grain growth play dominant roles. Based on this, the HAZ is proposed to categorize into three zones: the recrystallization heat-affected zone (RHAZ) with a Tp of 700~900 °C, the transition heat-affected zone (THAZ) with a Tp of 900~1000 °C, and the coarse grain heat-affected zone (CGHAZ) with a Tp of 1000~1300 °C. The recrystallization fraction was 29~44% in the RHAZ, rapidly increased to 87% in the THAZ, and exceeded 95% in the CGHAZ. The average grain size was 17~19 µm in the RHAZ, slightly increased to 22 µm in the THAZ, and ultimately increased to 37 µm in the CGHAZ. The yield strength in the RHAZ and THAZ was consistent with the change in recrystallization fraction, while in the CGHAZ, it satisfied the Hall-Petch relationship with grain size. In addition, compared with the base material, the Charpy impact absorbed energy at -196 °C decreased by 22% in the RHAZ, but slightly increased in the CGHAZ. This indicates that the theory of fine grain strengthening and toughening is not entirely applicable to the HAZ of the investigated high-Mn steel.